Paucisymptomatic opisthorchiasis in a non-endemic country: a neglected differential diagnosis?

CASE PRESENTATION: We report a case of opisthorchiasis in a 71-year-old woman with intermittent upper abdominal pain, whose cause had remained unclear for a long time. She grew up in Kazakhstan and moved to Germany more than 30 years ago. After positive serological testing for Opisthorchis during a recent visit to her home country, she presented at our clinic for further evaluation. Stool examination confirmed the presence of Opisthorchis eggs. The symptoms quickly resolved after treatment with praziquantel. Abdominal sonography revealed adenomyomatosis of the gallbladder fundus and multiple gallbladder polyps, most likely a consequence of chronic inflammation caused by the parasite. Sonographic surveillance was recommended with regard to a potentially increased risk of cholangiocarcinoma. DISCUSSION AND CONCLUSIONS: No certified serological test for opisthorchiasis is available in Germany and molecular or antigen-based tests for this infection are also largely unavailable. Diagnosis therefore has to rely on stool microscopy which requires the examination of multiple samples to ensure adequate sensitivity. Diagnosis is further complicated as symptoms are often nonspecific and liver flukes are usually not among the initial differential diagnoses. Missing the diagnosis, however, carries the risk of serious complications. Global travel and migration as well as recent autochthonous cases in the European Union underscore the need for increased vigilance for opisthorchiasis even in non-endemic areas.